Dr. Hahn on the Impact of Trastuzumab Emtansine in HER2+ Breast Cancer

Olwen Hahn, MD, an associate professor of medicine at the University of Chicago, discusses the impact of trastuzumab emtansine (T-DM1; Kadcyla) on the treatment of patients with HER2-positive breast cancer.

The agent was examined in the phase 3 KATHERINE trial (NCT01772472) vs trastuzumab (Herceptin) as adjuvant therapy in patients with HER2-positive breast cancer who have residual disease in the breast or axillary lymph nodes following preoperative therapy, according to Jones. KATHERINE was a landmark study, as its results changed the standard of care for this patient population, Hahn says. Data from this trial led to the May 2019 FDA approval of T-DM1 for patients with HER2-positive early breast cancer who have residual invasive disease following neoadjuvant trastuzumab and chemotherapy. 

Prior to this study, the standard of care for patients with residual disease was treatment with trastuzumab, Hahn notes. However, this study showed that in this high-risk patient population, switching to T-DM1 resulted in a 50% decrease in relative risk of invasive recurrence or death, and an 11.3% absolute improvement in invasive disease-free survival, Hahn concludes.